Mask, method of providing the same, and method of providing display panel using mask

ABSTRACT

A mask assembly includes a mask frame in which a first opening is defined, the mask frame including a front surface through which the first opening extends, and a deposition mask which is attached to the front surface of the mask frame and through which a plurality of second openings is defined. The mask frame includes an in which the front surface extends along a direction of gravity, the deposition mask includes an initial mask which is attached to the front surface of the mask frame in the thereof and through which the plurality of second openings is defined, and the of the mask frame having the front surface which extends along the direction of gravity disposes the first opening of the mask frame corresponding to all of the plurality of second openings of the initial mask along the direction of gravity.

This application a divisional application of U.S. application Ser. No.17/324,029 filed May 18, 2021, which claims priority to Korean PatentApplication No. 10-2020-0110613, filed on Aug. 31, 2020, and all thebenefits accruing therefrom under 35 U.S.C. § 119, the entire contentsof which are hereby incorporated by reference.

BACKGROUND (1) Field

The disclosure herein relates to a deposition mask, a method ofproviding (or manufacturing) the same, and a method of providing (ormanufacturing) a display panel using the deposition mask. Moreparticularly, the disclosure herein relates to a metal deposition mask,a method of providing the same, and a method of providing a displaypanel by using the metal deposition mask.

(2) Description of the Related Art

A display panel includes a plurality of pixels. Each of the pixelsincludes a driving element such as a transistor and a display elementsuch as an organic light-emitting diode. The display element may bedisposed by stacking an electrode and a light-emitting pattern on asubstrate.

The light-emitting pattern is patterned by using a deposition maskhaving a penetration hole (e.g., deposition hole) defined therein so asto be disposed in a region of the deposition mask. The light-emittingpattern may be provided to a target in a region thereof exposed tooutside the deposition mask by the penetration hole thereof.

SUMMARY

The disclosure provides a mask used to manufacture a large-area displaypanel and a method of manufacturing the mask which may improvereliability and reduce costs.

An embodiment provides a mask including a mask frame having a firstopening defined therein and a deposition mask having a plurality ofsecond openings defined therein, where the first opening overlaps all ofthe second openings.

In an embodiment, the deposition mask may be provided in plurality, andthe plurality of deposition masks may overlap the first opening.

In an embodiment, the first opening may be provided in plurality, thedeposition mask may be provided in plurality, and the deposition masksmay be disposed respectively corresponding to the first openings.

In an embodiment, the mask may further include a middle frame betweenthe mask frame and the deposition mask. The middle frame may include aplurality of third openings and the first opening may overlap all of thethird openings.

In an embodiment, the second openings may overlap one of the thirdopenings.

In an embodiment, the deposition mask and the mask frame may includemetal.

In an embodiment, a method of manufacturing a mask includes providing amask frame having a first opening defined therein, providing an initialdeposition mask having a plurality of second openings defined thereinwhich overlap the first opening on the front surface of the mask frame,combining the initial deposition mask with the mask frame to provide amask assembly, and removing a portion of the initial deposition mask toform the mask from the mask assembly. At the providing of the initialdeposition mask, the initial deposition mask is attached to a porouschuck and provided on the front surface of the mask frame.

In an embodiment, the front surface of the mask frame may be provided inparallel with the direction of gravity.

In an embodiment, the porous chuck may be provided in plurality.

In an embodiment, the portion of the initial deposition mask may beremoved by using a pulse laser.

In an embodiment, a region in which the pulse laser is provided may bebetween the second openings and the porous chuck.

In an embodiment, the region in which the pulse laser is provided may bebetween the porous chuck and the region in which the initial depositionmask and the mask frame are combined.

The method of manufacturing the mask may further include providing amiddle frame between the mask frame and the initial deposition mask, andthe initial deposition mask may be provided on the front surface of themiddle frame and combined with the middle frame.

In an embodiment, the porous chuck may be combined with the removedportion of the initial deposition mask.

In an embodiment, a method of manufacturing a display panel includesproviding a mask on a work substrate and forming a plurality oflight-emitting patterns on the work substrate with a depositionmaterial. The mask includes a mask frame having a first opening definedtherein and a deposition mask having a plurality of second openingsdefined therein, respectively corresponding to the light-emittingpatterns, where the first opening overlaps all of the second openings.

In an embodiment, the first opening may have an area corresponding tothe work substrate.

In an embodiment, the method may further include cutting the worksubstrate into a plurality of display panels after the forming of thelight-emitting patterns. The first opening is provided in plurality, theplurality of first openings correspond to the display panels,respectively, and the work substrate may entirely overlap the firstopenings.

In an embodiment, the method may further include providing a middleframe between the frame and the deposition mask and having a pluralityof third openings defined therein, and combining the deposition maskwith the middle frame. One of the third openings may overlap the secondopenings, and the first opening may overlap the third openings.

In an embodiment, at least one of the deposition mask and the mask framemay be melted, and the deposition mask and the mask frame may becombined.

In an embodiment, the first opening may have a single closed loop shapeon a plane.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theinvention. In the drawings:

FIG. 1 is a cross-sectional view of an embodiment of a display panel;

FIG. 2 is a cross-sectional view of an embodiment of a depositionapparatus;

FIGS. 3A and 3B are perspective views of an embodiment of a mask;

FIG. 4 is a perspective view of an embodiment of a mask;

FIGS. 5A to 5F illustrate an embodiment of a method of manufacturing amask;

FIGS. 6A and 6B illustrate an embodiment of a mask assembly;

FIGS. 7A and 7B illustrate an embodiment of a mask assembly; and

FIGS. 8A to 8C illustrate an embodiment of a porous chuck.

DETAILED DESCRIPTION

Hereinafter, embodiments of the invention will be described in detailwith reference to the accompanying drawings.

It will be understood that when an element (area, layer, portion, or thelike) is referred to as being related to another element such as being“on,” “connected to” or “coupled to” another element, it can be directlyon, connected or coupled to the other element or intervening elementsmay be present. In contrast, when an element (area, layer, portion, orthe like) is referred to as being related to another element such asbeing “directly on,” “directly connected to” or “directly coupled to”another element, no other element or intervening elements are present.

Like reference numerals refer to like elements throughout. Thethicknesses and the ratios and the dimensions of elements in thedrawings may be exaggerated for effective description of the technicalcontents.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein,“a”, “an,” “the,” and “at least one” do not denote a limitation ofquantity, and are intended to include both the singular and plural,unless the context clearly indicates otherwise. For example, “anelement” has the same meaning as “at least one element,” unless thecontext clearly indicates otherwise. “At least one” is not to beconstrued as limiting “a” or “an.” “Or” means “and/or.” As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms.

These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. For example, a first element, component, region, layer orsection discussed below could be termed a second element, component,region, layer or section without departing from the teachings of theinventive concept. Similarly, a second element, component, region, layeror section could be termed a first element, component, region, layer orsection.

Spatially relative terms, such as “below,” “lower,” “above,” “upper” andthe like, may be used herein for ease of description to describe oneelement or feature's relationship to another element(s) or feature(s) asillustrated in the figures. The terms used herein are relative conceptsand described on the basis of directions in the drawings.

It will be further understood that the terms “include” or “have”, whenused in this specification, specify the presence of stated features,integers, steps, operations, elements, components and/or groups thereof,but do not preclude the presence or addition of one or more otherfeatures, integers, steps, operations, elements, components, and/orgroups thereof.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, ±20%, ±10% or ±5% of the statedvalue.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Embodiments are described herein with reference to cross sectionillustrations that are schematic illustrations of idealized embodiments.As such, variations from the shapes of the illustrations as a result,for example, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments described herein should not be construed aslimited to the particular shapes of regions as illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing. For example, a region illustrated or described as flatmay, typically, have rough and/or nonlinear features. Moreover, sharpangles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims

A shape of a light-emitting pattern of a display panel may be controlleddepending on the shape of a penetration hole (e.g., deposition opening)of a deposition mask. In order to increase the production yield of adisplay panel including the light-emitting pattern, technologies relatedto facilities and methods of providing (or manufacturing) a large-areadeposition mask are being developed.

Hereinafter, the invention will be described in detail with reference tothe accompanying drawings.

FIG. 1 is a cross-sectional view of an embodiment of a display panel DP.The display panel DP may be a light-emitting display panel. FIG. 1illustrates a cross section corresponding to one pixel among a pluralityof pixels of the display panel DP. In this specification, a pixelincludes at least one transistor and one display element such as onelight-emitting element. FIG. 1 illustrates, as an example, a region inwhich two transistors T1 and T2 and a light-emitting diode OLED as alight-emitting element are disposed in a pixel.

As illustrated in FIG. 1 the display panel DP includes a base layer BL,a circuit element layer DP-CL disposed on the base layer BL, a displayelement layer DP-OLED disposed on the circuit element layer DP-CL, andan upper insulating layer TFL (e.g., encapsulation layer) disposed onthe display element layer DP-OLED.

The base layer BL may include a synthetic resin layer. In an embodimentof providing the display panel DP, the synthetic resin layer is disposedon a support substrate, and then a conductive material layer and aninsulating material layer are disposed on the synthetic resin layer. Inproviding the display panel DP, when the support substrate is removedfrom a remainder of the layers, the synthetic resin layer corresponds tothe base layer BL of the display panel DP.

The circuit element layer DP-CL includes at least one insulatingmaterial layer and one circuit element. The circuit element includes asignal line, a pixel driving circuit, and the like. Through a process ofproviding or forming an insulating material layer, a semiconductormaterial layer and a conductive material layer using coating, depositingand the like, and a process of patterning the insulating material layer,the semiconductor material layer and the conductive material layer usinga photolithography process, a circuit element layer DP-CL may beprovided or formed.

In an embodiment, the circuit element layer DP-CL includes a bufferlayer BFL, a barrier layer BRL, and first to seventh insulating layers10 to 70. The buffer layer BFL, the barrier layer BRL and the first toseventh insulating layers 10 to 70 may include either an inorganicmaterial film or an organic material film. The buffer layer BFL and thebarrier layer BRL may include an inorganic material film. At least oneamong the fifth to seventh insulating layers 50 to 70 may include anorganic material film.

FIG. 1 illustrates, as an example, an arrangement relation of a firstactive A1, a second active A2, a first gate G1, a second gate G2, afirst source S1, a second source S2, a first drain D1 and a second drainD2 which constitute a first transistor T1 and a second transistor T2. Inan embodiment, the first active A1 and the second active A2 may includedifferent materials. The first active A1 may include a polysiliconsemiconductor material, and the second active A2 may include a metaloxide semiconductor material. The first source S1 and the first drain D1are regions having a higher doping concentration than the first activeA1, and have a conductive property to function as electrodes. The secondsource S2 and the second drain D2 are regions in which the metal oxidesemiconductor material is reduced, and have a conductive property tofunction as electrodes.

In an embodiment, the first active A1 and the second active A2 mayinclude a same semiconductor material, and in this case, a stackedstructure of the circuit element layer DP-CL may be simplified.

The display element layer DP-OLED includes a pixel-defining film PDL anda light-emitting diode OLED. The light-emitting diode OLED may be anorganic light-emitting diode or a quantum dot light-emitting diode. Ananode AE is disposed on the seventh insulating layer 70. A pixel openingPOP of the pixel-defining film PDL may expose at least a portion of theanode AE to outside the pixel-defining film PDL. The pixel opening POPof the pixel-defining film PDL may define a light-emitting region PXA ofthe pixel. A non-light-emitting region NPXA of the pixel may be adjacentto the light-emitting region PXA. In an embodiment, thenon-light-emitting region NPXA may surround the light-emitting regionPXA in a plan view of the display panel DP.

A hole control layer HCL and an electron control layer ECL may bedisposed in common corresponding to both the light-emitting region PXAand the non-light-emitting region NPXA. A light-emitting layer EML maybe provided in the form of a pattern so as to correspond to the pixelopening POP. A cathode CE may be disposed in common corresponding toboth the light-emitting region PXA and the non-light-emitting regionNPXA.

The light-emitting layer EML which is a discrete pattern may be providedin a different process than the hole control layer HCL and the electroncontrol layer ECL which are each a film. In order to provide thelight-emitting layer EML as a discrete pattern having a shape, a maskassembly may be used. A discrete pattern provided by using the maskassembly may be referred to as a deposition pattern.

The hole control layer HCL and the electron control layer ECL may bedisposed in common in a plurality of pixels by using an open depositionmask. The light-emitting layer EML as a deposition pattern may bedisposed according to positions along the base layer BL which correspondto pixels by using a deposition mask otherwise referred to herein as afine metal mask (“FMM”).

The upper insulating layer TFL may include a plurality of thin films.The plurality of thin films may include an inorganic material film andan organic material film. The upper insulating layer TFL may include aninsulating material layer for encapsulating the display element layerDP-OLED and an insulating material layer for improving light outputefficiency.

FIG. 2 is a cross-sectional view of an embodiment of a depositionapparatus DA. The deposition apparatus DA may be used for a depositionprocess in providing of the display panel DP in FIG. 1 , particularlyfor providing of the light-emitting layer EML as a deposition pattern inthe deposition process.

As illustrated in FIG. 2 , the deposition apparatus DA includes adeposition chamber CB, a fixing member CM, a deposition source DS (e.g.,deposition material source) disposed inside the deposition chamber CB,and a mask MSK (hereinafter referred to as a mask assembly) disposedinside the deposition chamber CB. Although not illustrated separately,the deposition apparatus DA may further include an additional mechanicaldevice for implementing an in-line system.

The deposition condition of the deposition chamber CB may be set to avacuum state. The deposition chamber CB may include a floor surface, aceiling surface and side walls which connect the floor surface to theceiling surface. The floor surface of the deposition chamber CB is in aplane parallel to a plane defined by a first direction axis DR1 (e.g.,first direction D1 (see FIG. 3A)) and a second direction axis DR2 (e.g.second direction D2 (see FIG. 3A)) which cross each other. A thirddirection axis DR3 (e.g., third direction D3 (see FIG. 3A)) indicates adirection normal to the floor surface of the deposition chamber CB.Hereinafter, the first to third directions D1, D2 and D3 are defined asdirections indicated by each of the first to third direction axes DR1,DR2 and DR3, and refer to like reference numerals. The expression “on aplane” used hereinafter is set on the basis of a surface parallel to theplane defined by the first direction axis DR1 and the second directionaxis DR2 which cross each other. The expression “in a plan view” usedherein indicates viewing along a third direction D3. The thicknessdirection of components or layers may be defined along the thirddirection D3, without being limited thereto.

The fixing member CM is disposed inside the deposition chamber CB andfacing the deposition source DS, and fixes a position of the mask MSKwithin the deposition chamber CB. The fixing member CM may be installedto the ceiling surface. The fixing member CM may include a jig and/or arobot arm which holds the mask MSK to fix a position or location thereofwithin the deposition chamber CB.

The fixing member CM includes a body portion BD and a magnetic portionwhich is coupled to the body portion BD. The magnetic portion mayinclude a magnetic material MM (e.g., magnetic material portion)provided in plural including magnetic materials MM coupled to the bodyportion BD. The body portion BD may include a plate as a basic structurefor fixing the mask MSK to the fixing member CM, but is not limitedthereto. The magnetic materials MM may be disposed inside and/or outsidethe body portion BD. The magnetic materials MM may fix the mask MSK tothe fixing member CM by magnetic force.

The deposition source DS may evaporate a deposition material such as alight-emitting material and discharge the deposition material asdeposition vapor. The deposition vapor passes through penetration holesdefined in the mask MSK and is deposited onto a work substrate WS (e.g.,target substrate) in a pattern to provide a deposition pattern on thework substrate WS.

The mask MSK is disposed inside the deposition chamber CB and facing thedeposition source DS. The mask MSK which faces the work substrate WS maysupport the work substrate WS within the deposition chamber CB. The worksubstrate WS may include a glass substrate or a plastic substrate. Thework substrate WS may include a polymer layer disposed on a basesubstrate. In a process of providing the display panel, the basesubstrate may be removed and the polymer layer of the work substrate WSmay correspond to the base layer BL within the display panel DP of FIG.1 .

The mask MSK includes a deposition mask (hereinafter referred to as aunit mask MS) and a mask frame FM. The unit mask MS may be provided inplurality including a plurality of unit masks MS, and each of the unitmasks MS may correspond to a deposition mask for cell-based deposition.The unit mask MS is provided in combination with the mask frame FM. Adetailed description of this will be given later.

FIGS. 3A and 3B are perspective views of an embodiment of a maskassembly. FIG. 4 is a perspective view of an embodiment of a maskassembly. FIG. 3A illustrates a mask MSK which is horizontal and FIG. 3Billustrates an embodiment in which a unit mask MS is separated from themask frame FM. FIG. 4 illustrates a mask MSK which is upright.

As illustrated in FIG. 3A, the mask MSK includes a mask frame FM and aplurality of unit masks MS. The mask frame FM may have a rectangularshape with short sides extending along a first direction D1 and longsides extending along a second direction D2 intersecting each other. Themask frame FM has a thickness defined along a third direction D3 whichintersects each of the first direction D1 and the second direction D2.The third direction D3 indicates a direction which substantially andvertically crosses a plane defined by the first and second directions D1and D2 intersecting each other. Hereinafter, the expression “in a planview” in this specification may mean viewing along the third directionD3.

Portions of the mask frame FM may define a cell opening COP (e.g., firstopening or first deposition opening). The cell opening COP may beprovided in plural including a plurality of cell openings COP defined inthe mask frame FM. The cell openings COP may be arranged spaced apartfrom each other along at least one of the first direction D1 and thesecond direction D2. The cell openings COP may have a matrix arrangementalong the first direction D1 and the second direction D2.

On a plane, each of the cell openings COP may have a rectangular shape.In an embodiment, for example, the cell opening COP may have two longsides spaced apart along the first direction D1 and extending along thesecond direction D2. The cell opening COP may have two short sidesspaced apart along the second direction D2 and extending along the firstdirection D1. On the basis of the third direction D3, the cell openingsCOP may be defined to pass through the mask frame FM. That is, each ofthe cell openings COP may extend through an entirety of a thickness ofthe mask frame FM.

The plurality of unit masks MS are disposed on the mask frame FM. Theunit masks MS are disposed to non-overlap each other on a plane. Thatis, the unit masks MS may be adjacent to each other along the mask frameFM. The unit masks MS may be disposed corresponding to a number of thecell openings COP. In an embodiment, four of the unit masks MS areexemplarily illustrated to corresponding to a single one among the cellopenings COP.

Portions of the unit mask MS may define an opening OP (e.g., secondopening or second deposition opening) provided in plural including aplurality of openings OP (e.g., deposition openings) corresponding tothe cell opening COP. Solid portions of the unit mask MS may be spacedapart from each other to define the openings OP. The opening OP maysubstantially correspond to a deposition pattern such as thelight-emitting layer EML (see FIG. 1 ). A deposition material may bedeposited as a light-emitting layer EML onto the work substrate WSthrough the opening OP.

A unit mask MS is disposed to overlap one of the cell openings COP and acorresponding periphery of the cell opening COP of the mask frame FM.The unit mask MS may be combined with the mask frame FM at the peripheryof the cell opening COP. A detailed description of this will be givenlater.

Each of the unit masks MS may be a thin plate having a small thicknesswhen compared with a thickness of the mask frame FM. Each of the unitmasks MS and the mask frame FM may include a metal material such asstainless steel (“SUS”), Invar alloy, nickel (Ni) or cobalt (Co). In anembodiment, for example, the unit mask MS and the mask frame FM mayinclude Invar alloy. However, the materials of the unit mask MS and themask frame FM are not limited thereto.

The mask MSK may be provided in an upright state. As illustrated in FIG.4 , the mask MSK may be provided in an upright state so that a shortside of the mask MSK is parallel to the third direction D3 (e.g., adirection of gravity). The mask MSK which is upright disposes a frontsurface SF (see FIG. 5A) of the mask frame FM to which the unit mask MSis attached extended along the third direction D3.

The mask MSK illustrated in FIG. 4 may be an orientation of the mask MSKin both a process of providing the mask MSK (see FIG. 5B) and a timeimmediately after the providing of the mask MSK. In an embodiment ofproviding an initial mask assembly MSA, the mask MSK may be moved orstored in the orientation illustrated in FIG. 4 . Taking FIGS. 3A and 3Btogether with FIG. 4 , an attachment orientation of the mask frame FMhaving a front surface SF which extends along the direction of gravitydisposes the plurality of first openings (e.g., cell openings COP) ofthe mask frame FM respectively corresponding to the plurality ofdeposition masks (e.g., unit masks MS) along the direction of gravity.

In one or more embodiment of the invention, by orienting the mask MSK tobe upright (e.g., in an upright state or vertical state) in moving orstoring of the mask MSK, deformation of the mask MSK which may be causedby gravity during moving or storing of the initial mask assembly MSA maybe reduced or effectively prevented. Accordingly, the reliability of aprocess in which the mask MSK is provided may be improved.

An embodiment of a method of providing a display panel DP may includeproviding a mask assembly on a target substrate, and providing alight-emitting pattern of the display panel DP on the target substratethrough the mask assembly. The method may further include providing thelight-emitting pattern in plural including a plurality of light-emittingpatterns of a plurality of display panels respectively at target areasof the target substrate, and providing the plurality of display panelsseparated from each other. The mask assembly may further include a firstopening provided in plural including a plurality of first openingscorresponding to the plurality of display panels, respectively. Anattachment orientation of the mask frame FM having the front surface SFwhich extends along the direction of gravity disposes the plurality offirst openings of the mask frame FM respectively corresponding to thetarget areas of the target substrate along the direction of gravity.

FIGS. 5A to 5F illustrate an embodiment of a method of providing (ormanufacturing) an initial mask assembly MSA. FIGS. 5A to 5F illustratecross-sectional views of the initial mask assembly MSA which is in anupright orientation, taken along a third direction D3 on the basis of asingle one of the cell opening COP and a single one of the unit mask MSillustrated in FIG. 4 .

As illustrated in FIG. 5A, an initial unit mask MS_I (otherwise referredto as an initial mask or initial deposition mask) includes openings OPcorresponding to the openings OP of the unit mask MS. The initial unitmask MS_I is provided on a mask frame FM such as by movement of theinitial unit mask MS_I in the direction of the arrow. The initial unitmask MS_I may be moved by a porous chuck PS (e.g., holding tool). Aplanar area of the mask frame FM may be larger than a planar area of theinitial unit mask MS_I, especially for a dimension along the thirddirection D3. In an embodiment, for example, the initial unit mask MS_Imay have a length along the third direction D3 which is greater than alength of the unit mask MS in an upright orientation.

The porous chuck PS having the initial unit mask MS_I attached thereto,moves the initial unit mask MS_I toward a front surface SF of the maskframe FM. The porous chuck PS may be a vacuum chuck. The initial unitmask MS_I which is in a vertical orientation may be easily moved byusing the porous chuck PS. That is, the providing of the initial maskassembly MSA may include providing the initial deposition mask attachedto a holding tool (e.g., porous chuck PS) which maintains the initialdeposition mask parallel to the front surface SF of the mask frame FMwhich extends along the direction of gravity. In an embodiment, theinitial deposition mask is attached to a plurality of holding tools atopposing sides of the first opening of the mask frame FM which maintainthe initial deposition mask parallel to the front surface SF of the maskframe FM which extends along the direction of gravity.

As illustrated in FIGS. 5A and 5B, the initial unit mask MS_I is movedby the porous chuck PS and is contacted with the front surface SF of themask frame FM. The initial unit mask MS_I in contact with the mask frameFM remains attached to the porous chuck PS. Therefore, sliding of theinitial unit mask MS_I by gravity (in the direction opposite to thethird direction D3) is reduced or effectively prevented.

As illustrated in FIGS. 5C and 5D, the initial unit mask MS_I isattached to the mask frame FM such as by using a bonding tool DV1. Thebonding tool DV1 may be a welding tool or a laser oscillator. Thebonding tool DV1 provides a first beam IJ1 to the initial unit mask MS_Ialong a bonding line BL. The bonding line BL may be definedcorresponding to a position of the mask frame FM which is at a peripheryof the cell opening COP and outside the cell opening COP. The method mayinclude providing of the initial mask assembly MSA including the maskframe FM in the attachment orientation thereof and having the initialdeposition mask (e.g., initial unit mask MS_I) attached to the frontsurface SF of the mask frame FM which extends along the direction ofgravity.

The first beam IJ1 may be a thermic ray or a laser ray. A portion of theinitial unit mask MS_I and/or the mask frame FM may be melted by thefirst beam IJ1 so that the initial unit mask MS_I and the mask frame FMare attached to each other at the bonding line BL. Attachment of theinitial unit mask MS_I to the mask frame FM by melting of a portion ofthe initial unit mask MS_I and/or the mask frame FM defines a bondingportion BP (e.g., attachment area). The bonding portion BP may include ametallic oxide as a portion of the material of the initial unit maskMS_I. The bonding portion BP may be a direct bond between the initialunit mask MS_I and the mask frame FM. That is, the mask assembly mayinclude the deposition mask (e.g., unit mask MS) attached to the frontsurface SF of the mask frame FM by a direct bond in which a portion ofthe initial deposition mask or a portion of the mask frame FM is melted.

As illustrated in FIGS. 5E and 5F, the unit mask MS is provided byremoving a portion of the initial unit mask MS_I from the initial maskassembly MSA. A cutting tool DV2 may be used to separate a portion ofthe initial unit mask MS_I from a remaining portion thereof. The portionof the initial unit mask MS_I is separated by irradiating a second beamIJ2 along a trimming line TL (e.g., separation line). The trimming lineTL may be defined corresponding to a region between the bonding portionBP and a portion of the initial unit mask MS_I at which the porous chuckPS is contacted to the initial unit mask MS_I.

The remaining portion of the initial unit mask MS_I may provide a unitmask MS having an edge EG (e.g., outer edge). The trimming line TL ofthe initial unit mask MS_I may correspond to the edge EG of the unitmask MS as the remaining portion of the initial unit mask MS_I. That is,the method may further include providing a portion of the initialdeposition mask separated from a remainder of the initial depositionmask of the initial mask assembly MSA, to provide a deposition mask ofthe mask assembly as the remainder of the initial deposition mask.

The cutting tool DV2 may include various tools which provide the secondbeam IJ2 to the initial unit mask MS_I. In an embodiment, for example,the cutting tool DV2 may include a heat irradiator, a light irradiatoror a laser oscillator.

In an embodiment, the cutting tool DV2 may be a pulse laser oscillatorand includes a picosecond or femtosecond pulse laser oscillator.Accordingly, the second beam IJ2 may be a pulse laser beam.

Referring to FIGS. 5A through 5F, an embodiment of a mask assemblyincludes a mask frame FM in which a first opening (e.g., cell openingCOP) is defined, the mask frame FM including a front surface SF throughwhich the first opening extends, and a deposition mask (e.g., unit maskMS) which is attached to the front surface SF of the mask frame FM andthrough which a plurality of second openings (e.g., openings OP) isdefined. The mask frame FM includes an attachment orientation in whichthe front surface SF extends along a direction of gravity (e.g., thirddirection D3). The deposition mask includes an initial mask (e.g.,initial unit mask MS_I) which is attached to the front surface SF of themask frame FM in the attachment orientation thereof (e.g., while themask frame FM is vertical along the third direction D3) and throughwhich the plurality of second openings is defined. The attachmentorientation of the mask frame FM having the front surface SF whichextends along the direction of gravity disposes the first opening of themask frame FM corresponding to all of the plurality of second openingsof the initial mask along the direction of gravity.

According to one or more embodiment, by irradiating a fine pulse laserwith the second beam IJ2 to separate a portion of the initial unit maskMS_I from a remaining portion thereof, a burr that may occur in theinitial unit mask MS_I and/or deformation of the initial unit mask MS_Imay be minimized. Minimizing of a burr and/or deformation of the unitmask MS provided from the initial unit mask MS_I minimizes a gap betweenthe unit mask MS and the work substrate WS (see FIG. 2 ) which is incontact with the unit mask MS. As such, a process error rate inproviding a deposition pattern by a deposition process using the unitmask MS may be lowered. In addition, damage to the work substrate WSwhich may be caused by contact with the mask MSK may be reduced oreffectively prevented.

The second beam IJ2 may have a wavelength band. A wavelength band of thesecond beam IJ2 may be variously designed without being limited. In anembodiment, for example, when the wavelength band of the second beam IJ2is about 500 nanometers (nm), the cutting efficiency of the initial unitmask MS_I including an Invar material may be relatively high.

In an embodiment, a scanner may be disposed between the cutting tool DV2and the initial unit mask MS_I. The second beam IJ2, which passesthrough the scanner, may be irradiated onto each of the two trimminglines spaced apart from each other along the third direction D3 at thesame time. Accordingly, the cutting time of the initial unit mask MS_Imay be shortened. The scanner may be provided in singular or plural, andis not limited to any one embodiment.

FIGS. 6A and 6B illustrate an embodiment of a first initial maskassembly MSA1. FIG. 6A illustrates an embodiment of the first initialmask assembly MSA1 which is horizontal, and FIG. 6B illustrates anembodiment of the first initial mask assembly MSA1 which is upright. Theorientation illustrated in FIG. 6B may correspond to the orientationillustrated in FIG. 5B.

As illustrated in FIG. 6A, the first initial mask assembly MSA1 mayinclude a first mask frame FM1, a middle frame MF, and a first initialunit mask MS_I1 provided in plural including a plurality of firstinitial unit masks MS_I1. The initial mask assembly structure may mean astructure of an assembly in which the initial mask and a frame are incontact with each other.

A mask opening OP_F1 may be defined in the first mask frame FM1. Thefirst mask frame FM1 has a closed loop shape which defines the firstopening (e.g., mask opening OP_F1) of the first mask frame FM1. Sincethe first mask frame FM1 has only one of the mask opening OP_F1 definedtherein unlike the mask frame FM (see FIG. 3A) illustrated in FIG. 3A,the process of providing the first mask frame FM1 may be simplified.

The middle frame MF is disposed between the first initial unit masksMS_I1 and the first mask frame FM1 along the third direction D3. Themiddle frame MF may include a middle frame opening OP_W (e.g., thirdopening or third deposition opening) provided in plural including aplurality of middle frame openings OP_W. The middle frame openings OP Wmay correspond to the plurality of openings OP and the cell opening COPillustrated in FIG. 3B.

The first initial unit masks MS_I1 are disposed facing the first maskframe FM1 with the middle frame MF therebetween. The first initial unitmasks MS_I1 may be disposed respectively corresponding to the middleframe openings OP_W. In one or more embodiment, a planar shape of themask opening OP_F1 of the first mask frame FM1 may be simplified byfurther including the middle frame MF. The middle frame MF and/or thefirst initial unit masks MS_I1 may be provided with a relatively smallthickness when compared with the first mask frame FM1. According to oneor more embodiment, the planar shape of the first mask frame FM1 havinga relatively large thickness may be simplified by providing a pluralityof middle frame openings OP_W in the middle frame MF with relativelyeasy processability.

Referring to FIG. 6B, the middle frame MF is disposed on and facing thefront surface SF of the first mask frame FM1, and the first initial unitmask MS_I1 is disposed on an initial mask front surface. The firstinitial unit mask MS_I1 is coupled to the porous chucks PS1 and PS2 andprovided to contact the middle frame MF. In an embodiment, theattachment orientation of the first mask frame FM1 having the frontsurface SF which extends along the direction of gravity disposes thefirst opening (e.g., mask opening OP_F1) of the first mask frame FM1corresponding to all of the plurality of deposition masks (e.g.,respectively including the first initial unit masks MS_I1) along thedirection of gravity. The attachment orientation of the first mask frameFM1 having the front surface SF which extends along the direction ofgravity disposes the first opening of the first mask frame FM1 furthercorresponding to all of the plurality of third openings (e.g., middleframe openings OP_W) of the middle frame MF along the direction ofgravity.

With the first initial unit mask MS_I1 in contact with the middle frameMF, the first bonding line BL1 and the first trimming line TL1 may bedefined at opposing sides of the first initial unit mask MS_I1 at whichthe porous chucks PS1 and PS2 are respectively attached, with theopenings OP therebetween. Afterward, the middle frame MF and the firstinitial unit mask MS_I1 are combined to each other at the first bondingline BL1 such as by welding and the like. The first initial unit maskMS_I1 and the middle frame MF may be further attached to the first maskframe FM1 at the first bonding line BL1 without being limited thereto.Portions of the middle frame MF and the first initial unit mask MS_I1may be separated from remaining portions thereof, such as by cuttingalong the first trimming line TL1, while the first initial unit maskMS_I1 remains attached to and supported by the porous chucks PS1 and PS2until the first initial unit mask MS_I1 is finally provided.Accordingly, sagging of the first initial unit mask MS_I1 by gravityduring a mask assembly manufacturing process may be reduced oreffectively prevented.

In one or more embodiment, since the first initial mask assembly MSA1may be provided in a vertical state (e.g., upright position), separatesupport sticks for supporting the first initial unit masks MS_I1 whichare coupled to the first mask frame FM1 to prevent the first initialunit masks MS_I1 from sagging caused by gravity, may be omitted.Accordingly, the process may be simplified and the process costs may bereduced.

FIGS. 7A and 7B illustrate an embodiment of a second initial maskassembly MSA2. FIG. 7A illustrates the second initial mask assembly MSA2which is horizontal and FIG. 7B illustrates an embodiment of the secondinitial mask assembly MSA2 which is upright. The orientation illustratedin FIG. 7B may correspond to the orientation FIG. 5B.

As illustrated in FIG. 7A, a second initial unit mask MS_I2 may atension portion provided in plural such as including four tension parts.The second initial unit mask MS_I2 includes the tension parts protrudedalong the first direction D1 and the second direction D2 with respect tothe openings OP. A planar including all of the openings OP may define adeposition area of the second initial unit mask MS_I2, and the tensionportion may be extended from the deposition area to define an extendedportion of the second initial unit mask MS_I2. That is, the tensionportion of the second initial unit mask MS_I2 may extend further than aplanar area of the deposition area. The tension parts may be portions ofthe second initial unit mask MS_I2 at which the second initial unit maskMS_I2 is attached to the middle frame MF

As illustrated in FIG. 7B, the tension parts are disposed at the edge ofthe middle frame opening OP_W of the middle frame MF. The tension partsare respectively held by four porous chucks PS1, PS2, PS3 and PS4 andmay be moved toward the middle frame MF. According to one or moreembodiment, the mask assembly manufacturing process may be stablycarried out due to the tension parts included and support by the porouschucks PS1, PS2, PS3 and PS4 at the tension parts of the second initialunit mask MS_I2.

Since the second initial mask assembly MSA2 may be manufactured in avertical orientation, separate support sticks, which are coupled to thefirst mask frame FM1 to reduce or effectively prevent the second initialunit masks MS_I2 from sagging caused by gravity, may be omitted.Accordingly, the process may be simplified and the process costs may bereduced.

FIGS. 8A to 8C illustrate an embodiment of a porous chuck PS. FIG. 8A isa perspective view illustrating the porous chuck PS, FIG. 8B is across-sectional view illustrating the porous chuck PS and FIG. 8C is abottom view illustrating the porous chuck PS.

As illustrated in FIG. 8A, the porous chuck PS may include a couplingportion CTP and a connecting portion CNP. The coupling portion CTP is aportion to which an initial mask is removably attached and whichprovides a contact surface CTS which is contacted by the initial maskwhich is attached to the porous chuck PS at a bottom surface thereof.The connecting portion CNP is connected to the coupling portion CTP andis movable in the X direction DX, in the Y direction DY and in the Zdirection DZ. The coupling portion CTP is movable together with theconnecting portion CNP.

As illustrated in FIGS. 8B and 8C, the coupling portion CTP may includea body member IH and a contact portion RB (e.g., contact layer).Portions of the body member IH provide a fine hole MH provided in pluralincluding a plurality of fine holes MH and an inner space SP. The innerspace SP may be connected to a hole HH in the connecting portion CNP.When a vacuum is created by a controller (not illustrated), the airoutside the porous chuck PS flows into the porous chuck PS through thefine hole MH (e.g., input hole) and moves to the hole HH (e.g., outputhole) of the connecting portion CNP through the inner space SP.Accordingly, the porous chuck PS applying a vacuum disposes the initialmask attached to the contact surface CTS.

The porous chuck PS may further include the contact portion RB. Thecontact portion RB may include holes respectively corresponding to fineholes MH. The contact surface CTS of the porous chuck PS may besubstantially provided or defined by the contact portion RB. The contactportion RB may include or be formed of a material having ductility. Inan embodiment, for example, the contact portion RB may include apolymer, a rubber or the like. Accordingly, physical damage to theinitial mask which is in contact with the contact surface CTS may bereduced or effectively prevented.

According to one or more embodiment, when manufacturing a large-areamask assembly including a cell-based unit mask, sagging by gravity ofthe cell-based unit mask is reduced or effectively prevented.Accordingly, the reliability of a mask manufacturing process may beimproved, and it is possible to provide the large-area mask assembly ofhigh quality. In addition, according to one or more embodiment, aseparate support to minimize sagging of the cell-based unit mask may beomitted. Accordingly, the costs for the mask manufacturing process maybe reduced.

Although the above has been described with reference to embodiments,those skilled in the art or those of ordinary skill in the art willunderstand that various modifications and changes can be made within thescope that does not depart from the spirit and technical field of theinvention described in the claims to be described.

Accordingly, the technical scope of the invention should not be limitedto the content described in the detailed description of thespecification, but should be determined by the claims as described.

What is claimed is:
 1. A mask assembly comprising: a mask frame which afirst opening defined in; and a deposition mask which a plurality ofsecond openings defined in, wherein the first opening overlaps all ofthe second openings.
 2. The mask assembly of claim 1, wherein thedeposition mask is provided in plurality and the plurality of depositionmasks overlap the first opening.
 3. The mask assembly of claim 1,wherein: the first opening is provided in plurality; the deposition maskis provided in plurality; and the deposition masks are disposedrespectively corresponding to the first openings.
 4. The mask assemblyof claim 1, further comprising a middle frame disposed between the maskframe and the deposition mask, wherein a plurality of third openingsdefined in the middle frame and the first opening overlaps all of thethird openings.
 5. The mask assembly of claim 4, wherein the secondopenings overlap one of the third openings.
 6. The mask assembly ofclaim 1, wherein the deposition mask and the mask frame contain metal.7. A method for manufacturing a display panel, the method comprising:providing a mask assembly on a target substrate; and providing alight-emitting pattern of the display panel on the target substratethrough the mask assembly, wherein the mask assembly comprises: a maskframe in which a first opening is defined extended through a frontsurface of the mask frame; and a deposition mask which is attached tothe front surface of the mask frame and through which a second openingis defined corresponding to the light-emitting pattern of the displaypanel, wherein the mask frame includes an attachment orientation inwhich the front surface extends along a direction of gravity, thedeposition mask includes an initial mask which is attached to the frontsurface of the mask frame in the attachment orientation thereof andthrough which the second opening is defined, and the attachmentorientation of the mask frame having the front surface which extendsalong the direction of gravity disposes the first opening of the maskframe corresponding to the second opening of the initial mask along thedirection of gravity.
 8. The method of claim 7, wherein each of thefirst opening of the mask frame and the target substrate has a planararea, and the planar area of the first opening corresponds to the planararea of the target substrate.
 9. The method of claim 7, furthercomprising: providing the light-emitting pattern in plural including aplurality of light-emitting patterns of a plurality of display panelsrespectively at target areas of the target substrate, and providing theplurality of display panels separated from each other, wherein the maskframe further comprises the first opening provided in plural including aplurality of first openings corresponding to the plurality of displaypanels, respectively; and the attachment orientation of the mask framehaving the front surface which extends along the direction of gravitydisposes the plurality of first openings of the mask frame respectivelycorresponding to the target areas of the target substrate along thedirection of gravity.
 10. The method of claim 7, wherein the maskassembly further comprises a middle frame between the mask frame and theinitial mask and in which a third opening is defined, and the attachmentorientation of the mask frame having the front surface which extendsalong the direction of gravity disposes the first opening of the maskframe corresponding to the third opening in the middle frame along thedirection of gravity.
 11. The method of claim 7, wherein the maskassembly further comprises the deposition mask attached to the frontsurface of the mask frame by a direct bond in which a portion of thedeposition mask or a portion of the mask frame is melted.
 12. The methodof claim 7, wherein the mask frame has a closed loop shape which definesthe first opening of the mask frame.